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Peracchia C. Gap Junction Channel Regulation: A Tale of Two Gates-Voltage Sensitivity of the Chemical Gate and Chemical Sensitivity of the Fast Voltage Gate. Int J Mol Sci 2024; 25:982. [PMID: 38256055 PMCID: PMC10815820 DOI: 10.3390/ijms25020982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Gap junction channels are regulated by gates sensitive to cytosolic acidification and trans-junctional voltage (Vj). We propose that the chemical gate is a calmodulin (CaM) lobe. The fast-Vj gate is made primarily by the connexin's NH2-terminus domain (NT). The chemical gate closes the channel slowly and completely, while the fast-Vj gate closes the channel rapidly but incompletely. The chemical gate closes with increased cytosolic calcium concentration [Ca2+]i and with Vj gradients at Vj's negative side. In contrast, the fast-Vj gate closes at the positive or negative side of Vj depending on the connexin (Cx) type. Cxs with positively charged NT close at Vj's negative side, while those with negatively charged NT close at Vj's positive side. Cytosolic acidification alters in opposite ways the sensitivity of the fast-Vj gate: it increases the Vj sensitivity of negative gaters and decreases that of positive gaters. While the fast-Vj gate closes and opens instantaneously, the chemical gate often shows fluctuations, likely to reflect the shifting of the gate (CaM's N-lobe) in and out of the channel's pore.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University Rochester, Rochester, NY 14642-8711, USA
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2
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Oliveira MC, Cordeiro RM, Bogaerts A. Effect of lipid oxidation on the channel properties of Cx26 hemichannels: A molecular dynamics study. Arch Biochem Biophys 2023; 746:109741. [PMID: 37689256 DOI: 10.1016/j.abb.2023.109741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/10/2023] [Accepted: 09/05/2023] [Indexed: 09/11/2023]
Abstract
Intercellular communication plays a crucial role in cancer, as well as other diseases, such as inflammation, tissue degeneration, and neurological disorders. One of the proteins responsible for this, are connexins (Cxs), which come together to form a hemichannel. When two hemichannels of opposite cells interact with each other, they form a gap junction (GJ) channel, connecting the intracellular space of these cells. They allow the passage of ions, reactive oxygen and nitrogen species (RONS), and signaling molecules from the interior of one cell to another cell, thus playing an essential role in cell growth, differentiation, and homeostasis. The importance of GJs for disease induction and therapy development is becoming more appreciated, especially in the context of oncology. Studies have shown that one of the mechanisms to control the formation and disruption of GJs is mediated by lipid oxidation pathways, but the underlying mechanisms are not well understood. In this study, we performed atomistic molecular dynamics simulations to evaluate how lipid oxidation influences the channel properties of Cx26 hemichannels, such as channel gating and permeability. Our results demonstrate that the Cx26 hemichannel is more compact in the presence of oxidized lipids, decreasing its pore diameter at the extracellular side and increasing it at the amino terminus domains, respectively. The permeability of the Cx26 hemichannel for water and RONS molecules is higher in the presence of oxidized lipids. The latter may facilitate the intracellular accumulation of RONS, possibly increasing oxidative stress in cells. A better understanding of this process will help to enhance the efficacy of oxidative stress-based cancer treatments.
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Affiliation(s)
- Maria C Oliveira
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium.
| | - Rodrigo M Cordeiro
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados 5001, CEP 09210-580, Santo André, SP, Brazil
| | - Annemie Bogaerts
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium
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3
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Scott H, Dong L, Stevenson A, MacDonald AI, Srinivasan S, Massimi P, Banks L, Martin PE, Johnstone SR, Graham SV. The human discs large protein 1 interacts with and maintains connexin 43 at the plasma membrane in keratinocytes. J Cell Sci 2023; 136:jcs259984. [PMID: 37288673 PMCID: PMC10309592 DOI: 10.1242/jcs.259984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
Gap junction channels, composed of connexins, allow direct cell-to-cell communication. Connexin 43 (Cx43; also known as GJA1) is widely expressed in tissues, including the epidermis. In a previous study of human papillomavirus-positive cervical epithelial tumour cells, we identified Cx43 as a binding partner of the human homologue of Drosophila Discs large (Dlg1; also known as SAP97). Dlg1 is a member of the membrane associated-guanylate kinase (MAGUK) scaffolding protein family, which is known to control cell shape and polarity. Here, we show that Cx43 also interacts with Dlg1 in uninfected keratinocytes in vitro and in keratinocytes, dermal cells and adipocytes in normal human epidermis in vivo. Depletion of Dlg1 in keratinocytes did not alter Cx43 transcription but was associated with a reduction in Cx43 protein levels. Reduced Dlg1 levels in keratinocytes resulted in a reduction in Cx43 at the plasma membrane with a concomitant reduction in gap junctional intercellular communication and relocation of Cx43 to the Golgi compartment. Our data suggest a key role for Dlg1 in maintaining Cx43 at the plasma membrane in keratinocytes.
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Affiliation(s)
- Harry Scott
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Li Dong
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Andrew Stevenson
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Alasdair I. MacDonald
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Sharmila Srinivasan
- Translation Research Platform for Veterinary Biologicals, Chennai, Tamil Nadu, India
| | - Paola Massimi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Patricia E. Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK
| | - Scott R. Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke VA 24016, USA
| | - Sheila V. Graham
- MRC-University of Glasgow Centre for Virus Research, School of Infection and Immunity, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
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4
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Ca 2+-Dependent and -Independent Calmodulin Binding to the Cytoplasmic Loop of Gap Junction Connexins. Int J Mol Sci 2023; 24:ijms24044153. [PMID: 36835569 PMCID: PMC9961272 DOI: 10.3390/ijms24044153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Ca2+/calmodulin (Ca2+/CaM) interaction with connexins (Cx) is well-established; however, the mechanistic basis of regulation of gap junction function by Ca2+/CaM is not fully understood. Ca2+/CaM is predicted to bind to a domain in the C-terminal portion of the intracellular loop (CL2) in the vast majority of Cx isoforms and for a number of Cx-s this prediction has proved correct. In this study, we investigate and characterise both Ca2+/CaM and apo-CaM binding to selected representatives of each of the α, β and γ connexin family to develop a better mechanistic understanding of CaM effects on gap junction function. The affinity and kinetics Ca2+/CaM and apo-CaM interactions of CL2 peptides of β-Cx32, γ-Cx35, α-Cx43, α-Cx45 and α-Cx57 were investigated. All five Cx CL2 peptides were found to have high affinity for Ca2+/CaM with dissociation constants (Kd(+Ca)) from 20 to 150 nM. The limiting rate of binding and the rates of dissociation covered a broad range. In addition, we obtained evidence for high affinity Ca2+-independent interaction of all five peptides with CaM, consistent with CaM remaining anchored to gap junctions in resting cells. However, for the α-Cx45 and α-Cx57 CL2 peptides, Ca2+-dependent association at resting [Ca2+] of 50-100 nM is indicated in these complexes as one of the CaM Ca2+ binding sites displays high affinity with Kd of 70 and 30 nM for Ca2+, respectively. Furthermore, complex conformational changes were observed in peptide-apo-CaM complexes with the structure of CaM compacted or stretched by the peptide in a concentration dependent manner suggesting that the CL2 domain may undergo helix-to-coil transition and/or forms bundles, which may be relevant in the hexameric gap junction. We demonstrate inhibition of gap junction permeability by Ca2+/CaM in a dose dependent manner, further cementing Ca2+/CaM as a regulator of gap junction function. The motion of a stretched CaM-CL2 complex compacting upon Ca2+ binding may bring about the Ca2+/CaM block of the gap junction pore by a push and pull action on the CL2 C-terminal hydrophobic residues of transmembrane domain 3 (TM3) in and out of the membrane.
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5
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Liu Z, Xiao Z, Wang X, Zhang L, Zhang Z. Ion channel gene GJB2 influences the intercellular communication by Up-regulating the SPP1 signaling pathway identified by the single-cell RNA sequencing in lung adenocarcinoma. Front Oncol 2023; 13:1146976. [PMID: 37188183 PMCID: PMC10175797 DOI: 10.3389/fonc.2023.1146976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/12/2023] [Indexed: 05/17/2023] Open
Abstract
Objective Firstly, observe the prognostic significance and the biological functional effects of gap junction protein beta 2 (GJB2 or Cx26) in lung adenocarcinoma (LUAD). Subsequently, explore the role played by GJB2 in intercellular communication by single-cell RNA sequencing. Method We made a differential analysis of GJB2 expression through public databases and investigated the clinical characteristics and prognostic significance. ESTIMATE analysis and Tumor Immune Estimation Resource (TIMER) database were utilized to illustrate the association of GJB2 with immune infiltration and components of the tumor microenvironment. Gene Ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and Gene set enrichment analysis (GSEA) were performed to study the biological function of GJB2. Cell-cell communication was analyzed using the CellChat R package through sc-RNA data. Results GJB2 has an outstanding prognosis value in LUAD and a close relationship was found between GJB2 and immune infiltration in LUAD. GJB2 could participate in several tumor biological processes, including extracellular matrix remodeling and upregulation of multiple cancer-related active pathways. GJB2 related hub-genes influence intercellular communication through the SPP1 signaling pathway. Conclusion Our study illustrates one mechanism by which GJB2 exerts its cancer-specific relevant effects, that is, causing changes in intercellular communication through the SPP1 signaling pathway. Blockade of this pathway may limit the functional role of GJB2 and provide us with promising new perceptions for LUAD treatment.
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Oliveira MC, Verswyvel H, Smits E, Cordeiro RM, Bogaerts A, Lin A. The pro- and anti-tumoral properties of gap junctions in cancer and their role in therapeutic strategies. Redox Biol 2022; 57:102503. [PMID: 36228438 PMCID: PMC9557036 DOI: 10.1016/j.redox.2022.102503] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/06/2022] [Accepted: 10/06/2022] [Indexed: 11/24/2022] Open
Abstract
Gap junctions (GJs), essential structures for cell-cell communication, are made of two hemichannels (commonly called connexons), one on each adjacent cell. Found in almost all cells, GJs play a pivotal role in many physiological and cellular processes, and have even been linked to the progression of diseases, such as cancer. Modulation of GJs is under investigation as a therapeutic strategy to kill tumor cells. Furthermore, GJs have also been studied for their key role in activating anti-cancer immunity and propagating radiation- and oxidative stress-induced cell death to neighboring cells, a process known as the bystander effect. While, gap junction (GJ)-based therapeutic strategies are being developed, one major challenge has been the paradoxical role of GJs in both tumor progression and suppression, based on GJ composition, cancer factors, and tumoral context. Therefore, understanding the mechanisms of action, regulation, and the dual characteristics of GJs in cancer is critical for developing effective therapeutics. In this review, we provide an overview of the current understanding of GJs structure, function, and paradoxical pro- and anti-tumoral role in cancer. We also discuss the treatment strategies to target these GJs properties for anti-cancer responses, via modulation of GJ function.
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Affiliation(s)
- Maria C Oliveira
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium; Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados 5001, CEP 09210-580, Santo André, SP, Brazil.
| | - Hanne Verswyvel
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium; Center for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium
| | - Evelien Smits
- Center for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium
| | - Rodrigo M Cordeiro
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados 5001, CEP 09210-580, Santo André, SP, Brazil
| | - Annemie Bogaerts
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium
| | - Abraham Lin
- Plasma Lab for Applications in Sustainability and Medicine-Antwerp (PLASMANT), Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium; Center for Oncological Research (CORE), Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium
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7
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Crystal Chan SH, Griffin JM, Clemett CA, Brimble MA, O’Carroll SJ, Harris PWR. Synthesis and Biological Evaluation of Termini-Modified and Cyclic Variants of the Connexin43 Inhibitor Peptide5. Front Chem 2022; 10:877618. [PMID: 36176893 PMCID: PMC9513234 DOI: 10.3389/fchem.2022.877618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/20/2022] [Indexed: 11/25/2022] Open
Abstract
Peptide5 is a 12–amino acid mimetic peptide that corresponds to a region of the extracellular loop 2 (EL2) of connexin43. Peptide5 regulates both cellular communication with the cytoplasm (hemichannels) and cell-to-cell communication (gap junctions), and both processes are implicated in neurological pathologies. To address the poor in vivo stability of native peptide5 and to improve its activity, twenty-five novel peptide5 mimetics were designed and synthesized. All the analogues underwent biological evaluation as a hemichannel blocker and as a gap junction disruptor, and several were assessed for stability in human serum. From this study, it was established that several acylations on the N-terminus were tolerated in the hemichannel assay. However, the replacement of the L-Lys with an N-methylated L-Lys to give H-VDCFLSRPTE-N-MeKT-OH showed good hemichannel and gap junction activity and was more stable in human serum. The cyclic peptide variants generally were not tolerated in either the hemichannel and gap junction assay although several possessed outstanding stability in human serum.
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Affiliation(s)
| | - Jarred M. Griffin
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Connor A. Clemett
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Margaret A. Brimble
- School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Simon J. O’Carroll
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- *Correspondence: Simon J. O’Carroll, ; Paul W. R. Harris,
| | - Paul W. R. Harris
- School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
- *Correspondence: Simon J. O’Carroll, ; Paul W. R. Harris,
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8
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Lorusso G, Wyss CB, Kuonen F, Vannini N, Billottet C, Duffey N, Pineau R, Lan Q, Wirapati P, Barras D, Tancredi A, Lyck R, Lehr HA, Engelhardt B, Delorenzi M, Bikfalvi A, Rüegg C. Connexins orchestrate progression of breast cancer metastasis to the brain by promoting FAK activation. Sci Transl Med 2022; 14:eaax8933. [PMID: 36070364 DOI: 10.1126/scitranslmed.aax8933] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Brain metastasis is a complication of increasing incidence in patients with breast cancer at advanced disease stage. It is a severe condition characterized by a rapid decline in quality of life and poor prognosis. There is a critical clinical need to develop effective therapies to prevent and treat brain metastases. Here, we describe a unique and robust spontaneous preclinical model of breast cancer metastasis to the brain (4T1-BM2) in mice that has been instrumental in uncovering molecular mechanisms guiding metastatic dissemination and colonization of the brain. Key experimental findings were validated in the additional murine D2A1-BM2 model and in human MDA231-BrM2 model. Gene expression analyses and functional studies, coupled with clinical transcriptomic and histopathological investigations, identified connexins (Cxs) and focal adhesion kinase (FAK) as master molecules orchestrating breast cancer colonization of the brain. Cx31 promoted homotypic tumor cell adhesion, heterotypic tumor-astrocyte interaction, and FAK phosphorylation. FAK signaling prompted NF-κB activation inducing Lamc2 expression and laminin 332 (laminin 5) deposition, α6 integrin-mediated adhesion, and sustained survival and growth within brain parenchyma. In the MDA231-BrM2 model, the human homologous molecules CX43, LAMA4, and α3 integrin were involved. Systemic treatment with FAK inhibitors reduced brain metastasis progression. In conclusion, we report a spontaneous model of breast cancer metastasis to the brain and identified Cx-mediated FAK-NF-κB signaling as a mechanism promoting cell-autonomous and microenvironmentally controlled cell survival for brain colonization. Considering the limited therapeutic options for brain metastatic disease in cancer patients, we propose FAK as a therapeutic candidate to further pursue in the clinic.
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Affiliation(s)
- Girieca Lorusso
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland.,Division of Experimental Oncology, Multidisciplinary Oncology Center (CePO), Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Faculty of Biology and Medicine, Epalinges 1066, Switzerland.,National Center for Competence in Research (NCCR) Molecular Oncology, Swiss Institute of Experimental Cancer Research, Ecole Polytechnique Fédérale de Lausanne (ISREC-EPFL), Lausanne 1015, Switzerland
| | - Christof B Wyss
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland
| | - François Kuonen
- Division of Experimental Oncology, Multidisciplinary Oncology Center (CePO), Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Faculty of Biology and Medicine, Epalinges 1066, Switzerland.,National Center for Competence in Research (NCCR) Molecular Oncology, Swiss Institute of Experimental Cancer Research, Ecole Polytechnique Fédérale de Lausanne (ISREC-EPFL), Lausanne 1015, Switzerland
| | - Nicola Vannini
- Ludwig Institute for Cancer Research (LICR), Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Epalinges 1066, Switzerland
| | | | - Nathalie Duffey
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland
| | - Raphael Pineau
- INSERM U1029 and University of Bordeaux, Pessac Cedex 33615, France
| | - Qiang Lan
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland.,Division of Experimental Oncology, Multidisciplinary Oncology Center (CePO), Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Faculty of Biology and Medicine, Epalinges 1066, Switzerland.,National Center for Competence in Research (NCCR) Molecular Oncology, Swiss Institute of Experimental Cancer Research, Ecole Polytechnique Fédérale de Lausanne (ISREC-EPFL), Lausanne 1015, Switzerland
| | - Pratyaksha Wirapati
- Bioinformatics Core Facility, Swiss Institute for Bioinformatics (SIB), Lausanne 1015, Switzerland
| | - David Barras
- Bioinformatics Core Facility, Swiss Institute for Bioinformatics (SIB), Lausanne 1015, Switzerland
| | - Alessandro Tancredi
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland
| | - Ruth Lyck
- Theodor Kocher Institute, University of Bern (UNIBE), Bern 3012, Switzerland
| | - Hans-Anton Lehr
- Institute of Pathology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne 1011, Switzerland
| | - Britta Engelhardt
- Theodor Kocher Institute, University of Bern (UNIBE), Bern 3012, Switzerland
| | - Mauro Delorenzi
- Bioinformatics Core Facility, Swiss Institute for Bioinformatics (SIB), Lausanne 1015, Switzerland
| | - Andreas Bikfalvi
- INSERM U1029 and University of Bordeaux, Pessac Cedex 33615, France
| | - Curzio Rüegg
- Experimental and Translational Oncology, Pathology Unit, Department of Oncology Microbiology and Immunology (OMI), Faculty of Science and Medicine, University of Fribourg, Fribourg 1700, Switzerland.,Division of Experimental Oncology, Multidisciplinary Oncology Center (CePO), Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Faculty of Biology and Medicine, Epalinges 1066, Switzerland.,National Center for Competence in Research (NCCR) Molecular Oncology, Swiss Institute of Experimental Cancer Research, Ecole Polytechnique Fédérale de Lausanne (ISREC-EPFL), Lausanne 1015, Switzerland
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9
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Virus interactions with the actin cytoskeleton-what we know and do not know about SARS-CoV-2. Arch Virol 2022; 167:737-749. [PMID: 35102456 PMCID: PMC8803281 DOI: 10.1007/s00705-022-05366-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/06/2021] [Indexed: 12/13/2022]
Abstract
The actin cytoskeleton and actin-dependent molecular and cellular events are responsible for the organization of eukaryotic cells and their functions. Viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), depend on host cell organelles and molecular components for cell entry and propagation. Thus, it is not surprising that they also interact at many levels with the actin cytoskeleton of the host. There have been many studies on how different viruses reconfigure and manipulate the actin cytoskeleton of the host during successive steps of their life cycle. However, we know relatively little about the interactions of SARS-CoV-2 with the actin cytoskeleton. Here, we describe how the actin cytoskeleton is involved in the strategies used by different viruses for entry, assembly, and egress from the host cell. We emphasize what is known and unknown about SARS-CoV-2 in this regard. This review should encourage further investigation of the interactions of SARS-CoV-2 with cellular components, which will eventually be helpful for developing novel antiviral therapies for mitigating the severity of COVID-19.
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10
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Ling X, Peng S, Xu Y, Chu F. Beneficial effect of simvastatin on human umbilical vein endothelial cells gap junctions induced by TNF-α. Anim Cells Syst (Seoul) 2022; 26:10-18. [PMID: 35308127 PMCID: PMC8928848 DOI: 10.1080/19768354.2021.2023037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Although simvastatin has been shown to inhibit vascular permeability, which might be amplified via gap junction intercellular communication (GJIC), the underlying mechanism of action remains unclear. In the present study, we investigated the effects and mechanisms of simvastatin on endothelial cells GJIC. Specifically, human umbilical vein endothelial cells (HUVECs) were stimulated with TNF-α (10 ng/mL) alone or in combination with simvastatin (5 µM), and their effects on vascular endothelial cell GJIC tested via the scrape loading/dye transfer (SL/DT) assay. Next, we performed immunofluorescence, real-time PCR and western blot assays to analyze expression of Cx37, Cx40 and Cx43 in HUVECs. Results showed that GJIC activity in HUVECs was markedly elevated in HUVECs treated with TNF-α in combination with simvastatin. In addition, simvastatin treatment significantly upregulated expression of Cx37 and Cx40 but downregulated Cx43 mRNAs and proteins. Taken together, these marked changes indicated that simvastatin exerts its regulatory effects on gap junction function by upregulating Cx37 and Cx40 and downregulating Cx43 expression.
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Affiliation(s)
- Xiwen Ling
- School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Siyuan Peng
- School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Yaqin Xu
- School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Fujiang Chu
- School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
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11
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Niu G, Zhang X, Hong R, Yang X, Gu J, Song T, Hu Z, Chen L, Wang X, Xia J, Ke Z, Ren J, Hong L. GJA1 promotes hepatocellular carcinoma progression by mediating TGF-β-induced activation and the epithelial-mesenchymal transition of hepatic stellate cells. Open Med (Wars) 2021; 16:1459-1471. [PMID: 34693020 PMCID: PMC8486017 DOI: 10.1515/med-2021-0344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 08/12/2021] [Accepted: 09/10/2021] [Indexed: 12/24/2022] Open
Abstract
Introduction Gap junction protein, alpha 1 (GJA1), which is correlated with recurrences and unfavorable prognoses in hepatocellular carcinomas (HCCs), is one of the specific proteins expressed by activated hepatic stellate cells (HSCs). Methods Expression of GJA1 was compared between HCCs and nontumor tissues (NTs), between hepatic cirrhosis and NTs, and between primary and metastatic HCCs using transcriptomic datasets from the Gene Expression Omnibus and the Integrative Molecular Database of Hepatocellular Carcinoma. The in vitro activities of GJA1 were investigated in cultured HSCs and HCC cells. The underlying mechanism was characterized using Gene Set Enrichment Analysis and validated by western blotting. Results The expression of GJA1 was significantly increased in HCCs and hepatic cirrhosis compared to that in NTs. GJA1 was also overexpressed in pulmonary metastases from HCCs when compared with HCCs without metastasis. Overexpression of GJA1 promoted while knockdown of GJA1 inhibited proliferation and transforming growth factor (TGF)-β-mediated activation and migration of cultured HSCs. Overexpression of GJA1 by lentivirus infection promoted proliferation and migration, while conditioned medium from HSCs overexpressing GJA1 promoted migration but inhibited proliferation of Hep3B and PLC-PRF-5 cells. Lentivirus infection with shGJA1 or conditioned medium from shGJA1-infected HSCs inhibited the proliferation and migration of HCCLM3 cells that had a high propensity toward lung metastasis. Mechanistically, GJA1 induced the epithelial–mesenchymal transition (EMT) in HSCs and HCCLM3 cells. Conclusion GJA1 promoted HCC progression by inducing HSC activation and the EMT in HSCs. GJA1 is potentially regulated by TGF-β and thus may be a therapeutic target to inhibit HCC progression.
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Affiliation(s)
- Gengming Niu
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Xiaotian Zhang
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Runqi Hong
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Ximin Yang
- Department of Radiology, Dongying New District Hospital, Dongying, Shandong Province, 257000, People's Republic of China
| | - Jiawei Gu
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Tao Song
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Zhiqing Hu
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Liang Chen
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Xin Wang
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Jie Xia
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, Minhang District, Shanghai, 200240, People's Republic of China
| | - Zhongwei Ke
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, 801 Heqing Road, Minhang District, Shanghai, 200240, People's Republic of China
| | - Jun Ren
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, 801 Heqing Road, Minhang District, Shanghai, 200240, People's Republic of China
| | - Liang Hong
- Department of General Surgery, Shanghai Fifth People's Hospital, Fudan University, 801 Heqing Road, Minhang District, Shanghai, 200240, People's Republic of China
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Cell transdifferentiation in ocular disease: Potential role for connexin channels. Exp Cell Res 2021; 407:112823. [PMID: 34506760 DOI: 10.1016/j.yexcr.2021.112823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/02/2021] [Accepted: 09/05/2021] [Indexed: 11/22/2022]
Abstract
Cell transdifferentiation is the conversion of a cell type to another without requiring passage through a pluripotent cell state, and encompasses epithelial- and endothelial-mesenchymal transition (EMT and EndMT). EMT and EndMT are well defined processes characterized by a loss of epithelial/endothelial phenotype and gain in mesenchymal spindle shaped morphology, which results in increased cell migration and decreased apoptosis and cellular senescence. Such cells often develop invasive properties. Physiologically, these processes may occur during embryonic development and can resurface, for example, to promote wound healing in later life. However, they can also be a pathological process. In the eye, EMT, EndMT and cell transdifferentiation have all been implicated in development, homeostasis, and multiple diseases affecting different parts of the eye. Connexins, constituents of connexin hemichannels and intercellular gap junctions, have been implicated in many of these processes. In this review, we firstly provide an overview of the molecular mechanisms induced by transdifferentiation (including EMT and EndMT) and its involvement in eye diseases. We then review the literature for the role of connexins in transdifferentiation in the eye and eye diseases. The evidence presented in this review supports the need for more studies into the therapeutic potential for connexin modulators in prevention and treatment of transdifferentiation related eye diseases, but does indicate that connexin channel modulation may be an upstream and unifying approach for regulating these otherwise complex processes.
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13
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Gap Junction Channelopathies and Calmodulinopathies. Do Disease-Causing Calmodulin Mutants Affect Direct Cell-Cell Communication? Int J Mol Sci 2021; 22:ijms22179169. [PMID: 34502077 PMCID: PMC8431743 DOI: 10.3390/ijms22179169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/19/2021] [Accepted: 08/21/2021] [Indexed: 11/24/2022] Open
Abstract
The cloning of connexins cDNA opened the way to the field of gap junction channelopathies. Thus far, at least 35 genetic diseases, resulting from mutations of 11 different connexin genes, are known to cause numerous structural and functional defects in the central and peripheral nervous system as well as in the heart, skin, eyes, teeth, ears, bone, hair, nails and lymphatic system. While all of these diseases are due to connexin mutations, minimal attention has been paid to the potential diseases of cell–cell communication caused by mutations of Cx-associated molecules. An important Cx accessory protein is calmodulin (CaM), which is the major regulator of gap junction channel gating and a molecule relevant to gap junction formation. Recently, diseases caused by CaM mutations (calmodulinopathies) have been identified, but thus far calmodulinopathy studies have not considered the potential effect of CaM mutations on gap junction function. The major goal of this review is to raise awareness on the likely role of CaM mutations in defects of gap junction mediated cell communication. Our studies have demonstrated that certain CaM mutants affect gap junction channel gating or expression, so it would not be surprising to learn that CaM mutations known to cause diseases also affect cell communication mediated by gap junction channels.
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14
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Zhang Y, Zhou X, Zhu Y, Wang H, Xu J, Su Y. Current mechanisms of primordial follicle activation and new strategies for fertility preservation. Mol Hum Reprod 2021; 27:6128515. [PMID: 33538812 DOI: 10.1093/molehr/gaab005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/12/2021] [Indexed: 12/12/2022] Open
Abstract
Premature ovarian insufficiency (POI) is characterized by symptoms caused by ovarian dysfunction in patients aged <40 years. It is associated with a shortened reproductive lifespan. The only effective treatment for patients who are eager to become pregnant is IVF/Embryo Transfer (ET) using oocytes donated by young women. However, the use of the technique is constrained by the limited supply of oocytes and ethical issues. Some patients with POI still have some residual follicles in the ovarian cortex, which are not regulated by gonadotropin. These follicles are dormant. Therefore, activating dormant primordial follicles (PFs) to obtain high-quality oocytes for assisted reproductive technology may bring new hope for patients with POI. Therefore, this study aimed to explore the factors related to PF activation, such as the intercellular signaling network, the internal microenvironment of the ovary and the environment of the organism. In addition, we discussed new strategies for fertility preservation, such as in vitro activation and stem cell transplantation.
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Affiliation(s)
- Yan Zhang
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
| | - Xiaomei Zhou
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
| | - Ye Zhu
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
| | - Hanbin Wang
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
| | - Juan Xu
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
| | - Yiping Su
- Department of Gynecology, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing 210004, China
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15
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Garcia-Vega L, O’Shaughnessy EM, Albuloushi A, Martin PE. Connexins and the Epithelial Tissue Barrier: A Focus on Connexin 26. BIOLOGY 2021; 10:biology10010059. [PMID: 33466954 PMCID: PMC7829877 DOI: 10.3390/biology10010059] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary Tissues that face the external environment are known as ‘epithelial tissue’ and form barriers between different body compartments. This includes the outer layer of the skin, linings of the intestine and airways that project into the lumen connecting with the external environment, and the cornea of the eye. These tissues do not have a direct blood supply and are dependent on exchange of regulatory molecules between cells to ensure co-ordination of tissue events. Proteins known as connexins form channels linking cells directly and permit exchange of small regulatory signals. A range of environmental stimuli can dysregulate the level of connexin proteins and or protein function within the epithelia, leading to pathologies including non-healing wounds. Mutations in these proteins are linked with hearing loss, skin and eye disorders of differing severity. As such, connexins emerge as prime therapeutic targets with several agents currently in clinical trials. This review outlines the role of connexins in epithelial tissue and how their dysregulation contributes to pathological pathways. Abstract Epithelial tissue responds rapidly to environmental triggers and is constantly renewed. This tissue is also highly accessible for therapeutic targeting. This review highlights the role of connexin mediated communication in avascular epithelial tissue. These proteins form communication conduits with the extracellular space (hemichannels) and between neighboring cells (gap junctions). Regulated exchange of small metabolites less than 1kDa aide the co-ordination of cellular activities and in spatial communication compartments segregating tissue networks. Dysregulation of connexin expression and function has profound impact on physiological processes in epithelial tissue including wound healing. Connexin 26, one of the smallest connexins, is expressed in diverse epithelial tissue and mutations in this protein are associated with hearing loss, skin and eye conditions of differing severity. The functional consequences of dysregulated connexin activity is discussed and the development of connexin targeted therapeutic strategies highlighted.
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16
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Acosta ML, Mat Nor MN, Guo CX, Mugisho OO, Coutinho FP, Rupenthal ID, Green CR. Connexin therapeutics: blocking connexin hemichannel pores is distinct from blocking pannexin channels or gap junctions. Neural Regen Res 2021; 16:482-488. [PMID: 32985469 PMCID: PMC7996017 DOI: 10.4103/1673-5374.290097] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Compounds that block the function of connexin and pannexin protein channels have been suggested to be valuable therapeutics for a range of diseases. Some of these compounds are now in clinical trials, but for many of them, the literature is inconclusive about the molecular effect on the tissue, despite evidence of functional recovery. Blocking the different channel types has distinct physiological and pathological implications and this review describes current knowledge of connexin and pannexin protein channels, their function as channels and possible mechanisms of the channel block effect for the latest therapeutic compounds. We summarize the evidence implicating pannexins and connexins in disease, considering their homeostatic versus pathological roles, their contribution to excesive ATP release linked to disease onset and progression.
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Affiliation(s)
- Monica L Acosta
- School of Optometry and Vision Science; New Zealand National Eye Centre, University of Auckland; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand
| | - Mohd N Mat Nor
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; Faculty of Medicine, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - Cindy X Guo
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Odunayo O Mugisho
- Department of Ophthalmology, University of Auckland; Buchanan Ocular Therapeutics Unit, Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Frazer P Coutinho
- Department of Ophthalmology, University of Auckland, Auckland, New Zealand
| | - Ilva D Rupenthal
- Department of Ophthalmology, University of Auckland; Buchanan Ocular Therapeutics Unit, Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
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17
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Tonabersat Inhibits Connexin43 Hemichannel Opening and Inflammasome Activation in an In Vitro Retinal Epithelial Cell Model of Diabetic Retinopathy. Int J Mol Sci 2020; 22:ijms22010298. [PMID: 33396676 PMCID: PMC7794685 DOI: 10.3390/ijms22010298] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/18/2020] [Accepted: 12/25/2020] [Indexed: 01/04/2023] Open
Abstract
This study was undertaken to evaluate the connexin hemichannel blocker tonabersat for the inhibition of inflammasome activation and use as a potential treatment for diabetic retinopathy. Human retinal pigment epithelial cells (ARPE-19) were stimulated with hyperglycemia and the inflammatory cytokines IL-1β and TNFα in order to mimic diabetic retinopathy molecular signs in vitro. Immunohistochemistry was used to evaluate the effect of tonabersat treatment on NLRP3, NLRP1, and cleaved caspase-1 expression and distribution. A Luminex cytokine release assay was performed to determine whether tonabersat affected proinflammatory cytokine release. NLRP1 was not activated in ARPE-19 cells, and IL-18 was not produced under disease conditions. However, NLRP3 and cleaved caspase-1 complex formation increased with hyperglycemia and cytokine challenge but was inhibited by tonabersat treatment. It also prevented the release of proinflammatory cytokines IL-1β, VEGF, and IL-6. Tonabersat therefore has the potential to reduce inflammasome-mediated inflammation in diabetic retinopathy.
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18
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Andelova K, Egan Benova T, Szeiffova Bacova B, Sykora M, Prado NJ, Diez ER, Hlivak P, Tribulova N. Cardiac Connexin-43 Hemichannels and Pannexin1 Channels: Provocative Antiarrhythmic Targets. Int J Mol Sci 2020; 22:ijms22010260. [PMID: 33383853 PMCID: PMC7795512 DOI: 10.3390/ijms22010260] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiac connexin-43 (Cx43) creates gap junction channels (GJCs) at intercellular contacts and hemi-channels (HCs) at the peri-junctional plasma membrane and sarcolemmal caveolae/rafts compartments. GJCs are fundamental for the direct cardiac cell-to-cell transmission of electrical and molecular signals which ensures synchronous myocardial contraction. The HCs and structurally similar pannexin1 (Panx1) channels are active in stressful conditions. These channels are essential for paracrine and autocrine communication through the release of ions and signaling molecules to the extracellular environment, or for uptake from it. The HCs and Panx1 channel-opening profoundly affects intracellular ionic homeostasis and redox status and facilitates via purinergic signaling pro-inflammatory and pro-fibrotic processes. These conditions promote cardiac arrhythmogenesis due to the impairment of the GJCs and selective ion channel function. Crosstalk between GJCs and HCs/Panx1 channels could be crucial in the development of arrhythmogenic substrates, including fibrosis. Despite the knowledge gap in the regulation of these channels, current evidence indicates that HCs and Panx1 channel activation can enhance the risk of cardiac arrhythmias. It is extremely challenging to target HCs and Panx1 channels by inhibitory agents to hamper development of cardiac rhythm disorders. Progress in this field may contribute to novel therapeutic approaches for patients prone to develop atrial or ventricular fibrillation.
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Affiliation(s)
- Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Natalia Jorgelina Prado
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Emiliano Raul Diez
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
- Correspondence: ; Tel.: +421-2-32295-423
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19
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Jin EJ, Park S, Lyu X, Jin Y. Gap junctions: historical discoveries and new findings in the Caenorhabditiselegans nervous system. Biol Open 2020; 9:bio053983. [PMID: 32883654 PMCID: PMC7489761 DOI: 10.1242/bio.053983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Gap junctions are evolutionarily conserved structures at close membrane contacts between two cells. In the nervous system, they mediate rapid, often bi-directional, transmission of signals through channels called innexins in invertebrates and connexins in vertebrates. Connectomic studies from Caenorhabditis elegans have uncovered a vast number of gap junctions present in the nervous system and non-neuronal tissues. The genome also has 25 innexin genes that are expressed in spatial and temporal dynamic pattern. Recent findings have begun to reveal novel roles of innexins in the regulation of multiple processes during formation and function of neural circuits both in normal conditions and under stress. Here, we highlight the diverse roles of gap junctions and innexins in the C. elegans nervous system. These findings contribute to fundamental understanding of gap junctions in all animals.
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Affiliation(s)
- Eugene Jennifer Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Seungmee Park
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xiaohui Lyu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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20
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Peracchia C. Calmodulin-Cork Model of Gap Junction Channel Gating-One Molecule, Two Mechanisms. Int J Mol Sci 2020; 21:E4938. [PMID: 32668628 PMCID: PMC7404200 DOI: 10.3390/ijms21144938] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022] Open
Abstract
The Calmodulin-Cork gating model is based on evidence for the direct role of calmodulin (CaM) in channel gating. Indeed, chemical gating of cell-to-cell channels is sensitive to nanomolar cytosolic calcium concentrations [Ca2+]i. Calmodulin inhibitors and inhibition of CaM expression prevent chemical gating. CaMCC, a CaM mutant with higher Ca2+-sensitivity greatly increases chemical gating sensitivity (in CaMCC the NH2-terminal EF-hand pair (res. 9-76) is replaced by the COOH-terminal pair (res. 82-148). Calmodulin colocalizes with connexins. Connexins have high-affinity CaM binding sites. Several connexin mutants paired to wild-type connexins have a high gating sensitivity that is eliminated by inhibition of CaM expression. Repeated transjunctional voltage (Vj) pulses slowly and progressively close a large number of channels by the chemical/slow gate (CaM lobe). At the single-channel level, the chemical/slow gate closes and opens slowly with on-off fluctuations. The model proposes two types of CaM-driven gating: "Ca-CaM-Cork" and "CaM-Cork". In the first, gating involves Ca2+-induced CaM-activation. In the second, gating takes place without [Ca2+]i rise. The Ca-CaM-Cork gating is only reversed by a return of [Ca2+]i to resting values, while the CaM-Cork gating is reversed by Vj positive at the gated side.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University Rochester, Rochester, NY 14642, USA
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21
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Chemical and Voltage Gating of Gap Junction Channels Expressed in Xenopus Oocytes. Methods Mol Biol 2020. [PMID: 32548808 DOI: 10.1007/7651_2020_291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
In most tissues, cells in contact with each other directly intercommunicate via cell-to-cell channels aggregated at gap junctions. Direct cell-to-cell communication provides a fundamental mechanism for coordinating many cellular functions in mature and developing organs, as it enables free exchange of small cytosolic molecules. Gap junction channels are regulated by a chemical gating mechanism sensitive to cytosolic calcium concentration [Ca2+]i in the nanomolar range mediated by Ca2+-activated calmodulin (CaM). Evidence for the relevance of chemical regulation of gap junctional communication to cell function in health and disease prompted the development of methodologies aimed at quantitatively monitoring channel gating. A widely used method is the double voltage clamp of Xenopus laevis oocytes. Basically, this method involves pairing at the vegetal pole devitellinized oocytes in a conical well of a culture dish, inserting in each of them a current and a voltage microelectrode, establishing double voltage clamp and measuring junctional conductance (Gj) from voltage and current records.
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22
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Shao X, Lu X, Liao J, Chen H, Fan X. New avenues for systematically inferring cell-cell communication: through single-cell transcriptomics data. Protein Cell 2020; 11:866-880. [PMID: 32435978 PMCID: PMC7719148 DOI: 10.1007/s13238-020-00727-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/12/2020] [Indexed: 12/13/2022] Open
Abstract
For multicellular organisms, cell-cell communication is essential to numerous biological processes. Drawing upon the latest development of single-cell RNA-sequencing (scRNA-seq), high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues, which enables systematic cell-cell communication studies at a single-cell level. We first summarize a common workflow of cell-cell communication study using scRNA-seq data, which often includes data preparation, construction of communication networks, and result validation. Two common strategies taken to uncover cell-cell communications are reviewed, e.g., physically vicinal structure-based and ligand-receptor interaction-based one. To conclude, challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.
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Affiliation(s)
- Xin Shao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xiaoyan Lu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jie Liao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Huajun Chen
- College of Computer Science and Technology, Zhejiang University, Hangzhou, 310027, China.,The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Xiaohui Fan
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China. .,The Save Sight Institute, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2000, Australia.
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Acuña RA, Varas-Godoy M, Berthoud VM, Alfaro IE, Retamal MA. Connexin-46 Contained in Extracellular Vesicles Enhance Malignancy Features in Breast Cancer Cells. Biomolecules 2020; 10:E676. [PMID: 32353936 PMCID: PMC7277863 DOI: 10.3390/biom10050676] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 02/06/2023] Open
Abstract
Under normal conditions, almost all cell types communicate with their neighboring cells through gap junction channels (GJC), facilitating cellular and tissue homeostasis. A GJC is formed by the interaction of two hemichannels; each one of these hemichannels in turn is formed by six subunits of transmembrane proteins called connexins (Cx). For many years, it was believed that the loss of GJC-mediated intercellular communication was a hallmark in cancer development. However, nowadays this paradigm is changing. The connexin 46 (Cx46), which is almost exclusively expressed in the eye lens, is upregulated in human breast cancer, and is correlated with tumor growth in a Xenograft mouse model. On the other hand, extracellular vesicles (EVs) have an important role in long-distance communication under physiological conditions. In the last decade, EVs also have been recognized as key players in cancer aggressiveness. The aim of this work was to explore the involvement of Cx46 in EV-mediated intercellular communication. Here, we demonstrated for the first time, that Cx46 is contained in EVs released from breast cancer cells overexpressing Cx46 (EVs-Cx46). This EV-Cx46 facilitates the interaction between EVs and the recipient cell resulting in an increase in their migration and invasion properties. Our results suggest that EV-Cx46 could be a marker of cancer malignancy and open the possibility to consider Cx46 as a new therapeutic target in cancer treatment.
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Affiliation(s)
- Rodrigo A. Acuña
- Universidad del Desarrollo, Centro de Fisiología Celular e Integrativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile
- Universidad del Desarrollo, Programa de Comunicación Celular en Cáncer, Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Santiago 7780272, Chile
- Universidad del Desarrollo, Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 7780272, Chile;
| | - Manuel Varas-Godoy
- Cancer Cell Biology Lab., Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago 7780272, Chile;
| | | | - Ivan E. Alfaro
- Universidad del Desarrollo, Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 7780272, Chile;
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, Santiago 7780272, Chile
| | - Mauricio A. Retamal
- Universidad del Desarrollo, Centro de Fisiología Celular e Integrativa, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago 7780272, Chile
- Universidad del Desarrollo, Programa de Comunicación Celular en Cáncer, Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Santiago 7780272, Chile
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Connexin/Innexin Channels in Cytoplasmic Organelles. Are There Intracellular Gap Junctions? A Hypothesis! Int J Mol Sci 2020; 21:ijms21062163. [PMID: 32245189 PMCID: PMC7139775 DOI: 10.3390/ijms21062163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 12/21/2022] Open
Abstract
This paper proposes the hypothesis that cytoplasmic organelles directly interact with each other and with gap junctions forming intracellular junctions. This hypothesis originated over four decades ago based on the observation that vesicles lining gap junctions of crayfish giant axons contain electron-opaque particles, similar in size to junctional innexons that often appear to directly interact with junctional innexons; similar particles were seen also in the outer membrane of crayfish mitochondria. Indeed, vertebrate connexins assembled into hexameric connexons are present not only in the membranes of the Golgi apparatus but also in those of the mitochondria and endoplasmic reticulum. It seems possible, therefore, that cytoplasmic organelles may be able to exchange small molecules with each other as well as with organelles of coupled cells via gap junctions.
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Lloyd D, Millet CO, Williams CF, Hayes AJ, Pope SJA, Pope I, Borri P, Langbein W, Olsen LF, Isaacs MD, Lunding A. Functional imaging of a model unicell: Spironucleus vortens as an anaerobic but aerotolerant flagellated protist. Adv Microb Physiol 2020; 76:41-79. [PMID: 32408947 DOI: 10.1016/bs.ampbs.2020.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Advances in optical microscopy are continually narrowing the chasm in our appreciation of biological organization between the molecular and cellular levels, but many practical problems are still limiting. Observation is always limited by the rapid dynamics of ultrastructural modifications of intracellular components, and often by cell motility: imaging of the unicellular protist parasite of ornamental fish, Spironucleus vortens, has proved challenging. Autofluorescence of nicotinamide nucleotides and flavins in the 400-580 nm region of the visible spectrum, is the most useful indicator of cellular redox state and hence vitality. Fluorophores emitting in the red or near-infrared (i.e., phosphors) are less damaging and more penetrative than many routinely employed fluors. Mountants containing free radical scavengers minimize fluorophore photobleaching. Two-photon excitation provides a small focal spot, increased penetration, minimizes photon scattering and enables extended observations. Use of quantum dots clarifies the competition between endosomal uptake and exosomal extrusion. Rapid motility (161 μm/s) of the organism makes high resolution of ultrastructure difficult even at high scan speeds. Use of voltage-sensitive dyes determining transmembrane potentials of plasma membrane and hydrogenosomes (modified mitochondria) is also hindered by intracellular motion and controlled anesthesia perturbs membrane organization. Specificity of luminophore binding is always questionable; e.g. cationic lipophilic species widely used to measure membrane potentials also enter membrane-bounded neutral lipid droplet-filled organelles. This appears to be the case in S. vortens, where Coherent Anti-Stokes Raman Scattering (CARS) micro-spectroscopy unequivocally images the latter and simultaneous provides spectral identification at 2840 cm-1. Secondary Harmonic Generation highlights the highly ordered structure of the flagella.
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Affiliation(s)
- David Lloyd
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom; School of Engineering, Cardiff, Wales, United Kingdom
| | - Coralie O Millet
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | | | - Anthony J Hayes
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Simon J A Pope
- School of Chemistry, Main Building, Cardiff University, Cardiff, Wales, United Kingdom
| | - Iestyn Pope
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Paola Borri
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Wolfgang Langbein
- School of Physics and Astronomy, Cardiff University, Cardiff, Wales, United Kingdom
| | - Lars Folke Olsen
- Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Marc D Isaacs
- School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Anita Lunding
- Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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Peracchia C. Calmodulin-Mediated Regulation of Gap Junction Channels. Int J Mol Sci 2020; 21:E485. [PMID: 31940951 PMCID: PMC7014422 DOI: 10.3390/ijms21020485] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 12/25/2022] Open
Abstract
Evidence that neighboring cells uncouple from each other as one dies surfaced in the late 19th century, but it took almost a century for scientists to start understanding the uncoupling mechanism (chemical gating). The role of cytosolic free calcium (Ca2+i) in cell-cell channel gating was first reported in the mid-sixties. In these studies, only micromolar [Ca2+]i were believed to affect gating-concentrations reachable only in cell death, which would discard Ca2+i as a fine modulator of cell coupling. More recently, however, numerous researchers, including us, have reported the effectiveness of nanomolar [Ca2+]i. Since connexins do not have high-affinity calcium sites, the effectiveness of nanomolar [Ca2+]i suggests the role of Ca-modulated proteins, with calmodulin (CaM) being most obvious. Indeed, in 1981 we first reported that a CaM-inhibitor prevents chemical gating. Since then, the CaM role in gating has been confirmed by studies that tested it with a variety of approaches such as treatments with CaM-inhibitors, inhibition of CaM expression, expression of CaM mutants, immunofluorescent co-localization of CaM and gap junctions, and binding of CaM to peptides mimicking connexin domains identified as CaM targets. Our gating model envisions Ca2+-CaM to directly gate the channels by acting as a plug ("Cork" gating model), and probably also by affecting connexin conformation.
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Affiliation(s)
- Camillo Peracchia
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
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27
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Clarke H. Control of Mammalian Oocyte Development by Interactions with the Maternal Follicular Environment. Results Probl Cell Differ 2019; 63:17-41. [PMID: 28779312 DOI: 10.1007/978-3-319-60855-6_2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Development of animal germ cells depends critically on continuous contact and communication with the somatic compartment of the gonad. In females, each oocyte is enclosed within a follicle, whose somatic cells supply nutrients that sustain basal metabolic activity of the oocyte and send signals that regulate its differentiation. This maternal microenvironment thus plays an indispensable role in ensuring the production of fully differentiated oocytes that can give rise to healthy embryos. The granulosa cells send signals, likely membrane-associated Kit ligand, which trigger oocytes within resting-stage primordial follicles to initiate growth. During growth, the granulosa cells feed amino acids, nucleotides, and glycolytic substrates to the oocyte. These factors are necessary for the oocyte to complete its growth and are delivered via gap junctions that couple the granulosa cells to the oocyte. In a complementary manner, growing oocytes also release growth factors, notably growth-differentiation factor 9 and bone morphogenetic protein 15, which are necessary for proper differentiation of the granulosa cells and for these cells to support oocyte growth. During the late stages of oocyte growth, cyclic GMP that is synthesized by the granulosa cells and diffuses into the oocyte is required to prevent its precocious entry into meiotic maturation. Finally, at the early stages of maturation, granulosa cell signals promote the synthesis of a subset of proteins within the oocyte that enhance their ability to develop as embryos. Thus, the maternal legacy of the follicular microenvironment is witnessed by the fertilization of the ovulated oocyte and subsequent birth of healthy offspring.
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Affiliation(s)
- Hugh Clarke
- Department of Obstetrics and Gynecology, Research Institute of the McGill University Health Centre, McGill University, Room E.M0.2218, Glen Research Building, 100 Boul Decarie, Montreal, QC, Canada, H4A 3J1.
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28
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PRUCHA M, SEDIVY P, STADLER P, ZDRAHAL P, MATOSKA V, STRNAD H. Gene Expression in Patients With Abdominal Aortic Aneurysm – More Than Immunological Mechanisms Involved. Physiol Res 2019; 68:385-394. [DOI: 10.33549/physiolres.933905] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) is a serious condition of unclear pathogenesis and progression. Two samples were collected from 48 patients during AAA surgery. One sample was collected from the aneurysm, the other from the aneurysm proximal neck where the tissue did not exhibit any aneurysmal changes. Subsequently, gene expression profiles using microarrays (Illumina) were compared in RNA extracted from the samples. Overall, 2,185 genes were found to be upregulated and 2,100 downregulated; from which 158 genes had a different expression with FDR<0.05 (False Discovery Rate) and FC≥2 (Fold Change). Of this number, 115 genes were over-expressed and 43 under-expressed. The analysis of the gene list based on their biological pathways revealed that the regulation of inflammation was mediated by chemokine and cytokine signaling pathways, the integrin signaling pathway, and T and B cell activation. Moreover, a change was identified in the expression of genes involved in both intercellular and intracellular signaling systems.
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Affiliation(s)
- M PRUCHA
- Department of Clinical Biochemistry, Hematology and Immunology, Na Homolce Hospital, Prague, Czech Republic
| | - P SEDIVY
- Department of Vascular Surgery, Na Homolce Hospital, Prague, Czech Republic
| | - P STADLER
- Department of Vascular Surgery, Na Homolce Hospital, Prague, Czech Republic
| | - P ZDRAHAL
- Department of Vascular Surgery, Na Homolce Hospital, Prague, Czech Republic
| | - V MATOSKA
- Department of Clinical Biochemistry, Hematology and Immunology, Na Homolce Hospital, Prague, Czech Republic
| | - H STRNAD
- Genomics and Bioinformatics Core Facility, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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29
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A Barter Economy in Tumors: Exchanging Metabolites through Gap Junctions. Cancers (Basel) 2019; 11:cancers11010117. [PMID: 30669506 PMCID: PMC6356692 DOI: 10.3390/cancers11010117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 02/07/2023] Open
Abstract
To produce physiological functions, many tissues require their cells to be connected by gap junctions. Such diffusive coupling is important in establishing a cytoplasmic syncytium through which cells can exchange signals, substrates and metabolites. Often the benefits of connectivity become apparent solely at the multicellular level, leading to the notion that cells work for a common good rather than exclusively in their self-interest. In some tumors, gap junctional connectivity between cancer cells is reduced or absent, but there are notable cases where it persists or re-emerges in late-stage disease. Diffusive coupling will blur certain phenotypic differences between cells, which may seem to go against the establishment of population heterogeneity, a central pillar of cancer that stems from genetic instability. Here, building on our previous measurements of gap junctional coupling between cancer cells, we use a computational model to simulate the role of connexin-assembled channels in exchanging lactate and bicarbonate ions down their diffusion gradients. Based on the results of these simulations, we propose that an overriding benefit of gap junctional connectivity may relate to lactate/bicarbonate exchange, which would support an elevated metabolic rate in hypoxic tumors. In this example of barter, hypoxic cancer cells provide normoxic neighbors with lactate for mitochondrial oxidation; in exchange, bicarbonate ions, which are more plentiful in normoxic cells, are supplied to hypoxic neighbors to neutralize the H+ ions co-produced glycolytically. Both cells benefit, and so does the tumor.
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30
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Endothelin impacts on olfactory processing in rats. Behav Brain Res 2018; 362:1-6. [PMID: 30597250 DOI: 10.1016/j.bbr.2018.12.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/19/2018] [Accepted: 12/27/2018] [Indexed: 01/28/2023]
Abstract
In the olfactory epithelium, olfactory sensitive neurons and their axons are surrounded by glia-like cells called sustentacular cells, which maintain both the structural and ionic integrity of the olfactory mucosa. We have previously found that endothelin-1 (ET-1) can uncouple sustentacular cell gap junctions in vitro similarly as carbenoxolone, a known gap junction uncoupling agent. The role of gap junctions in odorant transduction remains controversial and we explored here if ET-1 naturally produced by the olfactory mucosa could impact odorant detection. Using calcium imaging on olfactory mucosa explant, we first confirmed that ET-1 uncouples gap junctions in an olfactory mucosa preparation preserving the tissue integrity. We next measured the olfactory epithelium responses to odorant stimulation using electro-olfactogram recordings. While the amplitude of the response was not modified by application of ET-1 and carbenoxolone, its repolarizing phase was slower after both treatments. We finally examined the behavioral performances of rat pups in an orientation test based on maternal odor recognition after intranasal instillations of ET-1 or carbenoxolone. While rat pups performances were decreased after ET-1 treatment, it was unchanged after carbenoxolone treatment. Overall, our results indicate that ET-1 modulates olfactory responses at least partly through gap junction uncoupling.
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31
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Cui J, Chen G, Perry AS, Abdi S. Transient Cell-to-Cell Signaling Before Mitosis in Cultures of Human Bone Marrow-Derived Mesenchymal Stem/Stromal Cells. Stem Cells Dev 2018; 28:120-128. [PMID: 30358482 DOI: 10.1089/scd.2018.0165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Some types of cells, if not all, that undergo signal exchanges in culture need to contact other cells for various reasons, such as cell-to-cell contact for growth inhibition. However, signal exchanges by cell-to-cell contact before proliferation have never been reported. Using time-lapse recording, we discovered the emergence of several astonishing cell-to-cell contact modes in bone marrow-derived mesenchymal stem/stromal cells (MSCs) before the cells divided. When the cells contacted with another, a huge temporary synapse-like structure formed for molecule exchanges; a cell-tissue particle was taken in by a recipient cell; two cell membranes formed infusion-like structure for a short time; and even a 20-μm long and 5-μm wide cell tail was grafted to another cell. A total of 87% of cells underwent cell-to-cell contact before dividing. After epidermal growth factor-green fluorescent protein (EGF-GFP) vectors were transfected into MSCs and the cells were cocultured with unmanipulated MSCs, the unmanipulated MSCs took in EGF-GFP particles from EGF-GFP expressed MSCs, immediately increased in mitogen genes, and then divided. These results suggest that cells which may lack signal molecules may need to obtain these molecules from other cells through various types of cell-to-cell contact, as mentioned above. Our study provided valuable information to better understand the behaviors of cell-to-cell contact and communication before mitosis.
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Affiliation(s)
- JianGuo Cui
- 1 Department of Pain Medicine, Anesthesiology, Critical Care and Pain Medicine Division, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Guanxing Chen
- 1 Department of Pain Medicine, Anesthesiology, Critical Care and Pain Medicine Division, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Anthony S Perry
- 2 Department of Pathology, Utah Valley Regional Medical Center, Proto, Utah
| | - Salahadin Abdi
- 1 Department of Pain Medicine, Anesthesiology, Critical Care and Pain Medicine Division, The University of Texas MD Anderson Cancer Center, Houston, Texas
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Steppan D, Geis L, Pan L, Gross K, Wagner C, Kurtz A. Lack of connexin 40 decreases the calcium sensitivity of renin-secreting juxtaglomerular cells. Pflugers Arch 2018; 470:969-978. [PMID: 29427253 PMCID: PMC10751884 DOI: 10.1007/s00424-018-2119-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/24/2018] [Accepted: 02/02/2018] [Indexed: 11/29/2022]
Abstract
The so-called calcium paradoxon of renin describes the phenomenon that exocytosis of renin from juxtaglomerular cells of the kidney is stimulated by lowering of the extracellular calcium concentration. The yet poorly understood effect of extracellular calcium on renin secretion appears to depend on the function of the gap junction protein connexin 40 (Cx40) in renin-producing cells. This study aimed to elucidate the role of Cx40 for the calcium dependency of renin secretion in more detail by investigating if Cx40 function is really essential for the influence of extracellular calcium on renin secretion, if and how Cx40 affects intracellular calcium dynamics in renin-secreting cells and if Cx40-mediated gap junctional coupling of renin-secreting cells with the mesangial cell area is relevant for the influence of extracellular calcium on renin secretion. Renin secretion was studied in isolated perfused mouse kidneys. Calcium measurements were performed in renin-producing cells of microdissected glomeruli. The ultrastructure of renin-secreting cells was examined by electron microscopy. We found that Cx40 was not essential for stimulation of renin secretion by lowering of the extracellular calcium concentration. Instead, Cx40 increased the sensitivity of renin secretion response towards lowering of the extracellular calcium concentration. In line, the sensitivity and dynamics of intracellular calcium in response to lowering of extracellular calcium were dampened when renin-secreting cells lacked Cx40. Disruption of gap junctional coupling of renin-secreting cells by selective deletion of Cx40 from mesangial cells, however, did not change the stimulation of renin secretion by lowering of the extracellular calcium concentration. Deletion of Cx40 from renin cells but not from mesangial cells was associated with a shift of renin expression from perivascular cells of afferent arterioles to extraglomerular mesangial cells. Our findings suggest that Cx40 is not directly involved in the regulation of renin secretion by extracellular calcium. Instead, it appears that in renin-secreting cells of the kidney lacking Cx40, intracellular calcium dynamics and therefore also renin secretion are desensitized towards changes of extracellular calcium. Whether the dampened calcium response of renin-secreting cells lacking Cx40 function results from a direct involvement of Cx40 in intracellular calcium regulation or from the cell type shift of renin expression from perivascular to mesangial cells remains to be clarified. In any case, Cx40-mediated gap junctional coupling between renin and mesangial cells is not relevant for the calcium paradoxon of renin secretion.
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Affiliation(s)
- Dominik Steppan
- Institute of Physiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
| | - Lisa Geis
- Clinic for Nephrology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Lin Pan
- Department of Pathology, Brigham and Women's Hospital, 652 NRB, 77 Ave Louis Pasteur, Boston, MA, 02115, USA
| | - Kenneth Gross
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Elm and Carlton Sts, Buffalo, NY, 14263-0001, USA
| | - Charlotte Wagner
- Institute of Physiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Armin Kurtz
- Institute of Physiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
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33
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Zhang L, Feng T, Spicer LJ. The role of tight junction proteins in ovarian follicular development and ovarian cancer. Reproduction 2018; 155:R183-R198. [PMID: 29374086 DOI: 10.1530/rep-17-0503] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 01/26/2018] [Indexed: 01/01/2023]
Abstract
Tight junctions (TJ) are protein structures that control the transport of water, ions and macromolecules across cell layers. Functions of the transmembrane TJ protein, occluding (OCLN) and the cytoplasmic TJ proteins, tight junction protein 1 (TJP1; also known as zona occludens protein-1), cingulin (CGN) and claudins (CLDN) are reviewed, and current evidence of their role in the ovarian function is reviewed. Abundance of OCLN, CLDNs and TJP1 mRNA changed during follicular growth. In vitro treatment with various growth factors known to affect ovarian folliculogenesis indicated that CGN, OCLN and TJP1 are hormonally regulated. The summarized studies indicate that expression of TJ proteins (i.e., OCLN, CLDN, TJP1 and CGN) changes with follicle size in a variety of vertebrate species but whether these changes in TJ proteins are increased or decreased depends on species and cell type. Evidence indicates that autocrine, paracrine and endocrine regulators, such as fibroblast growth factor-9, epidermal growth factor, androgens, tumor necrosis factor-α and glucocorticoids may modulate these TJ proteins. Additional evidence presented indicates that TJ proteins may be involved in ovarian cancer development in addition to normal follicular and luteal development. A model is proposed suggesting that hormonal downregulation of TJ proteins during ovarian follicular development could reduce barrier function (i.e., selective permeability of molecules between theca and granulosa cells) and allow for an increase in the volume of follicular fluid as well as allow additional serum factors into the follicle that may directly impact granulosa cell functions.
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Affiliation(s)
- Lingna Zhang
- Department of Animal ScienceOklahoma State University, Stillwater, Oklahoma, USA
| | - Tao Feng
- Institute of Animal Husbandry and Veterinary MedicineBeijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Leon J Spicer
- Department of Animal ScienceOklahoma State University, Stillwater, Oklahoma, USA
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Manera M, Sayyaf Dezfuli B, DePasquale JA, Giari L. Pigmented macrophages and related aggregates in the spleen of european sea bass dosed with heavy metals: Ultrastructure and explorative morphometric analysis. Microsc Res Tech 2018; 81:351-364. [PMID: 29318746 DOI: 10.1002/jemt.22986] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 11/08/2022]
Abstract
The ultrastructure and morphometrics of pigmented macrophages (PMs) were assessed in the spleen of European sea bass experimentally dosed with Cd and Hg. PMs occurred either as solitary cells or as variably structured aggregations, defined as macrophage aggregates (MAs). Light microscopy revealed a high degree of morphological heterogeneity amongst MAs of all experimental groups. At the ultrastructural level, MAs showed a heterogeneous pigment content that was not influenced by the treatment. Cytoplasm rarefaction/vacuolation and euchromatic nuclei, were observed in PMs of dosed fish. Undosed and Cd-dosed samples differ significantly with regard to the following morphometric features: the Minor axis of the best fitting ellipse, Aspect Ratio, and Roundness. In Cd-dosed fish, MAs showed reduced size and complexity. Lacunarity showed significant differences between undosed and both Cd and Hg-dosed samples. These results suggest that heavy metals, and especially Cd, may influence the dynamics of PM aggregation/disaggregation. Variability in splenic MAs was observed both by light and electron microscopy. However, only the morphometric techniques adequately and objectively described the phenomenon, allowing a quantitative/statistical comparison of morphology among experimental groups. These morphometric analyses could be usefully applied in toxicological and ecotoxicological, as well as morpho-functional studies.
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Affiliation(s)
- Maurizio Manera
- Faculty of Biosciences, Food and Environmental Technologies, University of Teramo, Teramo, I-64100, Italy
| | - Bahram Sayyaf Dezfuli
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, I-44121, Italy
| | | | - Luisa Giari
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, I-44121, Italy
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35
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Clarke HJ. Regulation of germ cell development by intercellular signaling in the mammalian ovarian follicle. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2018; 7:10.1002/wdev.294. [PMID: 28892263 PMCID: PMC5746469 DOI: 10.1002/wdev.294] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/21/2017] [Accepted: 08/02/2017] [Indexed: 12/21/2022]
Abstract
Prior to ovulation, the mammalian oocyte undergoes a process of differentiation within the ovarian follicle that confers on it the ability to give rise to an embryo. Differentiation comprises two phases-growth, during which the oocyte increases more than 100-fold in volume as it accumulates macromolecules and organelles that will sustain early embryogenesis; and meiotic maturation, during which the oocyte executes the first meiotic division and prepares for the second division. Entry of an oocyte into the growth phase appears to be triggered when the adjacent granulosa cells produce specific growth factors. As the oocyte grows, it elaborates a thick extracellular coat termed the zona pellucida. Nonetheless, cytoplasmic extensions of the adjacent granulosa cells, termed transzonal projections (TZPs), enable them to maintain contact-dependent communication with the oocyte. Through gap junctions located where the TZP tips meet the oocyte membrane, they provide the oocyte with products that sustain its metabolic activity and signals that regulate its differentiation. Conversely, the oocyte secretes diffusible growth factors that regulate proliferation and differentiation of the granulosa cells. Gap junction-permeable products of the granulosa cells prevent precocious initiation of meiotic maturation, and the gap junctions also enable oocyte maturation to begin in response to hormonal signals received by the granulosa cells. Development of the oocyte or the somatic compartment may also be regulated by extracellular vesicles newly identified in follicular fluid and at TZP tips, which could mediate intercellular transfer of macromolecules. Oocyte differentiation thus depends on continuous signaling interactions with the somatic cells of the follicle. WIREs Dev Biol 2018, 7:e294. doi: 10.1002/wdev.294 This article is categorized under: Gene Expression and Transcriptional Hierarchies > Cellular Differentiation Signaling Pathways > Cell Fate Signaling Early Embryonic Development > Gametogenesis.
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Affiliation(s)
- Hugh J Clarke
- Department of Obstetrics and Gynecology, Research Institute of the McGill University Health Centre, McGill University, Montreal, Canada
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36
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Mazaré N, Gilbert A, Boulay AC, Rouach N, Cohen-Salmon M. Connexin 30 is expressed in a subtype of mouse brain pericytes. Brain Struct Funct 2017; 223:1017-1024. [PMID: 29143947 DOI: 10.1007/s00429-017-1562-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 11/02/2017] [Indexed: 12/11/2022]
Abstract
Pericytes are mural cells of blood microvessels which play a crucial role at the neurovascular interface of the central nervous system. They are involved in the regulation of blood-brain barrier integrity, angiogenesis, clearance of toxic metabolites, capillary hemodynamic responses, and neuroinflammation, and they demonstrate stem cell activity. Morphological and molecular studies to characterize brain pericytes recently pointed out some heterogeneity in pericyte population. Nevertheless, a clear definition of pericyte subtypes is still lacking. Here, we demonstrate that a fraction of brain pericytes express Connexin 30 (Cx30), a gap junction protein, which, in the brain parenchyma, was thought to be exclusively found in astrocytes. Cx30 could thus be a candidate protein in the composition of the gap junction channels already described between endothelial cells and pericytes. It could also form hemichannels or acts in a channel-independent manner to regulate pericyte morphology, as already observed in astrocytes. Altogether, our results suggest that Cx30 defines a novel brain pericyte subtype.
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Affiliation(s)
- Noémie Mazaré
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de La Recherche Scientifique CNRS, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale INSERM, U1050/Neuroglial Interactions in Cerebral Physiopathology, 75231, Paris Cedex 05, France.,University Pierre et Marie Curie, ED, N°158, 75005, Paris, France.,MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005, Paris, France
| | - Alice Gilbert
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de La Recherche Scientifique CNRS, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale INSERM, U1050/Neuroglial Interactions in Cerebral Physiopathology, 75231, Paris Cedex 05, France.,University Pierre et Marie Curie, ED, N°158, 75005, Paris, France.,MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005, Paris, France
| | - Anne-Cécile Boulay
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de La Recherche Scientifique CNRS, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale INSERM, U1050/Neuroglial Interactions in Cerebral Physiopathology, 75231, Paris Cedex 05, France.,University Pierre et Marie Curie, ED, N°158, 75005, Paris, France.,MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005, Paris, France
| | - Nathalie Rouach
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de La Recherche Scientifique CNRS, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale INSERM, U1050/Neuroglial Interactions in Cerebral Physiopathology, 75231, Paris Cedex 05, France.,University Pierre et Marie Curie, ED, N°158, 75005, Paris, France.,MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005, Paris, France
| | - Martine Cohen-Salmon
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de La Recherche Scientifique CNRS, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale INSERM, U1050/Neuroglial Interactions in Cerebral Physiopathology, 75231, Paris Cedex 05, France. .,University Pierre et Marie Curie, ED, N°158, 75005, Paris, France. .,MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005, Paris, France.
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Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
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Kulshrestha R, Burton-Jones S, Antoniadi T, Rogers M, Jaunmuktane Z, Brandner S, Kiely N, Manuel R, Willis T. Deletion of P2 promoter of GJB1 gene a cause of Charcot-Marie-Tooth disease. Neuromuscul Disord 2017; 27:766-770. [PMID: 28601552 DOI: 10.1016/j.nmd.2017.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/23/2017] [Accepted: 05/01/2017] [Indexed: 11/25/2022]
Abstract
X-linked Charcot-Marie-Tooth disease (CMT) is the second most common cause of CMT, and is usually caused by mutations in the gap junction protein beta 1 (GJB1) gene. This gene has nerve specific P2 promoter that work synergistically with SOX10 and EGR2 genes to initiate transcription. Mutation in this region is known to cause Schwann cell dysfunction. A single large family of X linked peripheral neuropathy was identified in our practice. Next generation sequencing for targeted panel assay identified an upstream exon-splicing deletion identified extending from nucleotide c.-5413 to approximately - c.-49. This matches the sequence of 32 nucleotides at positions c.*218-*249 in the 3'UTR downstream of the GJB1 gene. The deleted fragment included the entire P2 promoter region. The deletion segregated with the disease. To our knowledge a deletion of the P2 promoter alone as a cause of CMT has not been reported previously.
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Affiliation(s)
- R Kulshrestha
- Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, UK.
| | - S Burton-Jones
- Bristol Genetics Laboratory, North Bristol NHS Trust, Southmead Hospital, Bristol, UK
| | - T Antoniadi
- West Midlands Molecular Genetics Lab, Birmingham, UK
| | - M Rogers
- Cardiff and Vale UHB - Medical Genetics, UK
| | | | | | - N Kiely
- Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, UK
| | - R Manuel
- Royal Stoke University Hospital, Newcastle Road, Stoke-on-Trent, UK
| | - T Willis
- Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, UK
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39
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Nectin spot: a novel type of nectin-mediated cell adhesion apparatus. Biochem J 2017; 473:2691-715. [PMID: 27621480 DOI: 10.1042/bcj20160235] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/23/2016] [Indexed: 01/10/2023]
Abstract
Nectins are Ca(2+)-independent immunoglobulin (Ig) superfamily cell adhesion molecules constituting a family with four members, all of which have three Ig-like loops at their extracellular regions. Nectins play roles in the formation of a variety of cell-cell adhesion apparatuses. There are at least three types of nectin-mediated cell adhesions: afadin- and cadherin-dependent, afadin-dependent and cadherin-independent, and afadin- and cadherin-independent. In addition, nectins trans-interact with nectin-like molecules (Necls) with three Ig-like loops and other Ig-like molecules with one to three Ig-like loops. Furthermore, nectins and Necls cis-interact with membrane receptors and integrins, some of which are associated with the nectin-mediated cell adhesions, and play roles in the regulation of many cellular functions, such as cell polarization, movement, proliferation, differentiation, and survival, co-operatively with these cell surface proteins. The nectin-mediated cell adhesions are implicated in a variety of diseases, including genetic disorders, neural disorders, and cancers. Of the three types of nectin-mediated cell adhesions, the afadin- and cadherin-dependent apparatus has been most extensively investigated, but the examples of the third type of apparatus independent of afadin and cadherin are recently increasing and its morphological and functional properties have been well characterized. We review here recent advances in research on this type of nectin-mediated cell adhesion apparatus, which is named nectin spot.
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40
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Abstract
PURPOSE OF REVIEW To describe the current knowledge on the cross-talk between connexins and microRNAs (miRs) in bone cells. RECENT FINDINGS Connexins play a crucial role on bone development and maintenance, and disruptions in their abundance or localization can affect how bone perceives and responds to mechanical, hormonal, and pharmacological stimuli. Connexin expression can be modified by miRs, which modulate connexin mRNA and protein levels. Recently, different manners by which miRs and connexins can interact in bone have been identified, including mechanisms that mediate miR exchange between cells in direct contact through gap junctions, or between distant cells via extracellular vesicles (EVs). SUMMARY We bring to light the relationship between miRs and connexins in bone tissue, with special focus on regulatory effects of miRs and connexins on gene expression, as well as the mechanisms that mediate miR exchange between cells in direct contact through gap junctions, or between distant cells via EVs.
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41
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Guo R, Si R, Scott BT, Makino A. Mitochondrial connexin40 regulates mitochondrial calcium uptake in coronary endothelial cells. Am J Physiol Cell Physiol 2017; 312:C398-C406. [PMID: 28122731 PMCID: PMC5407023 DOI: 10.1152/ajpcell.00283.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 01/30/2023]
Abstract
Connexins (Cxs) are a group of integral membrane proteins that can form gap junctions between adjacent cells. Recently, it was reported that Cx43 is expressed not only in the plasma membrane but also in the inner mitochondrial membrane and that it regulates mitochondrial functions. Cx40 is predominantly expressed in vascular endothelial cells (ECs) and plays an important role in the electrical propagation between ECs and endothelial/smooth muscle cells. However, it is unknown whether Cx40 is expressed in the mitochondria and what the role of mitochondrial Cx40 is in endothelial functions. We observed in coronary ECs that Cx40 protein was expressed in the mitochondria, as determined by Western blot and immunofluorescence studies. We found that mouse coronary ECs (MCECs) isolated from Cx40 knockout (Cx40 KO) mice exhibited significantly lower resting mitochondrial calcium concentration ([Ca2+]mito) than MCECs from wild-type (WT) mice. After increase in cytosolic Ca2+ concentration ([Ca2+]cyto) with cyclopiazonic acid, calcium uptake into the mitochondria was significantly attenuated in MCECs from Cx40 KO mice compared with WT MCECs. There was no difference in resting [Ca2+]cyto and store-operated calcium entry in MCECs from WT and Cx40 KO mice. We also detected a significant decrease in the concentration of mitochondrial reactive oxygen species (ROS) in Cx40 KO MCECs. Cx40 overexpression in ECs significantly increased resting [Ca2+]mito level and calcium uptake by mitochondria in response to increased [Ca2+]cyto and augmented mitochondrial ROS production. These data suggest that mitochondrial Cx40 contributes to the regulation of mitochondrial calcium homeostasis.
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Affiliation(s)
- Rui Guo
- Department of Physiology, The University of Arizona, Tucson, Arizona; and
| | - Rui Si
- Department of Physiology, The University of Arizona, Tucson, Arizona; and
| | - Brian T Scott
- Department of Medicine, University of California, San Diego, La Jolla, California
| | - Ayako Makino
- Department of Physiology, The University of Arizona, Tucson, Arizona; and
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42
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Meda P. Gap junction proteins are key drivers of endocrine function. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:124-140. [PMID: 28284720 DOI: 10.1016/j.bbamem.2017.03.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 01/07/2023]
Abstract
It has long been known that the main secretory cells of exocrine and endocrine glands are connected by gap junctions, made by a variety of connexin species that ensure their electrical and metabolic coupling. Experiments in culture systems and animal models have since provided increasing evidence that connexin signaling contributes to control the biosynthesis and release of secretory products, as well as to the life and death of secretory cells. More recently, genetic studies have further provided the first lines of evidence that connexins also control the function of human glands, which are central to the pathogenesis of major endocrine diseases. Here, we summarize the recent information gathered on connexin signaling in these systems, since the last reviews on the topic, with particular regard to the pancreatic beta cells which produce insulin, and the renal cells which produce renin. These cells are keys to the development of various forms of diabetes and hypertension, respectively, and combine to account for the exploding, worldwide prevalence of the metabolic syndrome. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva Medical School, Switzerland.
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43
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Abstract
Recent discoveries on the delivery of small- and large-size molecules and organelles to the oocytes/eggs from external sources, such as surrounding somatic cells, body fluids, and sperm, change our understanding of female germ cells' (oocytes and eggs) self-containment and individuality. In this chapter, we will summarize present-day knowledge on sources and presumptive functions of different types of exogenous molecules and organelles delivered to the animal oocytes and eggs.
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Affiliation(s)
- Malgorzata Kloc
- The Houston Methodist Research Institute, Houston, TX, USA. .,Department of Surgery, The Houston Methodist Hospital, 6550 Fannin St., Houston, TX, 77030, USA.
| | - Jacek Z Kubiak
- CNRS UMR 6290, Cell Cycle Group, Institute of Genetics and Development of Rennes, Rennes, France.,University of Rennes 1, Faculty of Medicine, Rennes, France.,Department of Regenerative Medicine, Military Institute of Hygiene and Epidemiology (WIHE), Warsaw, Poland
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44
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Abstract
Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. Although many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field.
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Affiliation(s)
- Trond Aasen
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences
Fondamentales et Appliquées, Université de Poitiers, Poitiers,
France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, The Life
Sciences Institute, University of British Columbia, Vancouver, British
Columbia, Canada
| | - Paul D. Lampe
- Translational Research Program, Fred Hutchinson Cancer Research
Center, Seattle, United States
| | - Dale W. Laird
- (Co-corresponding authors) Correspondence to
T.A. () and D.W.L.
()
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Munger SJ, Davis MJ, Simon AM. Defective lymphatic valve development and chylothorax in mice with a lymphatic-specific deletion of Connexin43. Dev Biol 2016; 421:204-218. [PMID: 27899284 DOI: 10.1016/j.ydbio.2016.11.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 12/17/2022]
Abstract
Lymphatic valves (LVs) are cusped luminal structures that permit the movement of lymph in only one direction and are therefore critical for proper lymphatic vessel function. Congenital valve aplasia or agenesis can, in some cases, be a direct cause of lymphatic disease. Knowledge about the molecular mechanisms operating during the development and maintenance of LVs may thus aid in the establishment of novel therapeutic approaches to treat lymphatic disorders. In this study, we examined the role of Connexin43 (Cx43), a gap junction protein expressed in lymphatic endothelial cells (LECs), during valve development. Mouse embryos with a null mutation in Cx43 (Gja1) were previously shown to completely lack mesenteric LVs at embryonic day 18. However, interpreting the phenotype of Cx43-/- mice was complicated by the fact that global deletion of Cx43 causes perinatal death due to heart defects during embryogenesis. We have now generated a mouse model (Cx43∆LEC) with a lymphatic-specific ablation of Cx43 and show that the absence of Cx43 in LECs causes a delay (rather than a complete block) in LV initiation, an increase in immature valves with incomplete leaflet elongation, a reduction in the total number of valves, and altered lymphatic capillary patterning. The physiological consequences of these lymphatic changes were leaky valves, insufficient lymph transport and reflux, and a high incidence of lethal chylothorax. These results demonstrate that the expression of Cx43 is specifically required in LECs for normal development of LVs.
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Affiliation(s)
| | - Michael J Davis
- Dept. of Medical Pharmacology & Physiology, University of Missouri School of Medicine, Columbia, MO, USA.
| | - Alexander M Simon
- Department of Physiology, University of Arizona, Tucson AZ 85724, USA.
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46
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Kim Y, Griffin JM, Harris PWR, Chan SHC, Nicholson LFB, Brimble MA, O'Carroll SJ, Green CR. Characterizing the mode of action of extracellular Connexin43 channel blocking mimetic peptides in an in vitro ischemia injury model. Biochim Biophys Acta Gen Subj 2016; 1861:68-78. [PMID: 27816754 DOI: 10.1016/j.bbagen.2016.11.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/19/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Non-selective Connexin43 hemichannels contribute to secondary lesion spread. The hemichannel blocking peptidomimetic Peptide5, derived from the second extracellular loop of the human Connexin43 protein, prevents lesion spread and reduces vascular permeability in preclinical models of central nervous system injury. The molecular mode of action of Peptide5, however, was unknown and is described here. METHODS Human cerebral microvascular endothelial cells and APRE-19 cells were used. Scrape loading was used to assess gap junction function and hypoxic, acidic ion-shifted Ringer solution induced ATP release used to assess hemichannel function. Peptide modifications, including amino acid substitutions and truncations, and competition assays were used to demonstrate Peptide5 functional specificity and site of action respectively. RESULTS Peptide5 inhibits Connexin43 hemichannel-mediated ATP release by acting on extracellular loop two of Connexin43, adjacent to its matching sequence within the protein. Precise sequence specificity is important for hemichannel block, but less so for uncoupling of gap junction channels (seen only at high concentrations). The SRPTEKT motif is central to Peptide5 function but on its own is not sufficient to inhibit hemichannels. Both the SRPTEKT motif and Peptide5 reduce gap junction communication, but neither uncoupling below 50%. CONCLUSIONS Reduced gap junction coupling at high peptide concentrations appears to be relatively non-specific. However, Peptide5 at low concentrations acts upon extracellular loop two of Connexin43 to block hemichannels in a precise, sequence specific manner. GENERAL SIGNIFICANCE The concentration dependent and sequence specific action of Peptide5 supports its development for the treatment of retinal injury and chronic disease, as well as other central nervous system injury and disease conditions.
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Affiliation(s)
- Yeri Kim
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Jarred M Griffin
- Centre for Brain Research, Department of Anatomy Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Paul W R Harris
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland, New Zealand; School of Biological Sciences, New Zealand
| | - Sin Hang Crystal Chan
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Louise F B Nicholson
- Centre for Brain Research, Department of Anatomy Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland, New Zealand; School of Biological Sciences, New Zealand
| | - Simon J O'Carroll
- Centre for Brain Research, Department of Anatomy Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Private Bag 92019, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland, New Zealand.
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Willebrords J, Crespo Yanguas S, Maes M, Decrock E, Wang N, Leybaert L, Kwak BR, Green CR, Cogliati B, Vinken M. Connexins and their channels in inflammation. Crit Rev Biochem Mol Biol 2016; 51:413-439. [PMID: 27387655 PMCID: PMC5584657 DOI: 10.1080/10409238.2016.1204980] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Inflammation may be caused by a variety of factors and is a hallmark of a plethora of acute and chronic diseases. The purpose of inflammation is to eliminate the initial cell injury trigger, to clear out dead cells from damaged tissue and to initiate tissue regeneration. Despite the wealth of knowledge regarding the involvement of cellular communication in inflammation, studies on the role of connexin-based channels in this process have only begun to emerge in the last few years. In this paper, a state-of-the-art overview of the effects of inflammation on connexin signaling is provided. Vice versa, the involvement of connexins and their channels in inflammation will be discussed by relying on studies that use a variety of experimental tools, such as genetically modified animals, small interfering RNA and connexin-based channel blockers. A better understanding of the importance of connexin signaling in inflammation may open up towards clinical perspectives.
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Affiliation(s)
- Joost Willebrords
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Sara Crespo Yanguas
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Michaël Maes
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
| | - Elke Decrock
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Nan Wang
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Ghent
University, De Pintelaan 185, 9000 Ghent, Belgium; Elke Decrock: Tel: +32 9 332 39
73, Nan Wang: Tel: +32 9 332 39 38, Luc Leybaert: Tel: +32 9 332 33 66
| | - Brenda R. Kwak
- Department of Pathology and Immunology and Division of Cardiology,
University of Geneva, Rue Michel-Servet 1, CH-1211 Geneva, Switzerland; Brenda R.
Kwak: Tel: +41 22 379 57 37
| | - Colin R. Green
- Department of Ophthalmology and New Zealand National Eye Centre,
University of Auckland, New Zealand; Colin R. Green: Tel: +64 9 923 61 35
| | - Bruno Cogliati
- Department of Pathology, School of Veterinary Medicine and Animal
Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87,
05508-270 São Paulo, Brazil; Bruno Cogliati: Tel: +55 11 30 91 12 00
| | - Mathieu Vinken
- Department of In Vitro Toxicology and
Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels,
Belgium; Joost Willebrords: + Tel: 32 2 477 45 87, Michaël Maes: Tel: +32 2
477 45 87, Sara Crespo Yanguas: Tel: +32 2 477 45 87
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48
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Connexin43 in retinal injury and disease. Prog Retin Eye Res 2016; 51:41-68. [DOI: 10.1016/j.preteyeres.2015.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/25/2015] [Accepted: 09/27/2015] [Indexed: 12/26/2022]
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49
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Becker DL, Phillips AR, Duft BJ, Kim Y, Green CR. Translating connexin biology into therapeutics. Semin Cell Dev Biol 2015; 50:49-58. [PMID: 26688335 DOI: 10.1016/j.semcdb.2015.12.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 12/26/2022]
Abstract
It is 45 years since gap junctions were first described. Universities face increasing commercial pressures and declining federal funding, with governments and funding foundations showing greater interest in gaining return on their investments. This review outlines approaches taken to translate gap junction research to clinical application and the challenges faced. The need for commercialisation is discussed and key concepts behind research patenting briefly described. Connexin channel roles in disease and injury are also discussed, as is identification of the connexin hemichannel as a therapeutic target which appears to play a role in both the start and perpetuation of the inflammasome pathway. Furthermore connexin hemichannel opening results in vascular dieback in acute injury and chronic disease. Translation to human indications is illustrated from the perspective of one connexin biotechnology company, CoDa Therapeutics, Inc.
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Affiliation(s)
- David L Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | | | | | - Yeri Kim
- Department of Ophthalmology and New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology and New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
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50
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Nesmiyanov PP, Tolkachev BE, Strygin AV. ZO-1 expression shows prognostic value in chronic B cell leukemia. Immunobiology 2015; 221:6-11. [PMID: 26306999 DOI: 10.1016/j.imbio.2015.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/17/2015] [Accepted: 08/11/2015] [Indexed: 01/10/2023]
Abstract
Connexin-mediated gap junctions are vital for tumor cell function. Intracellular pathways of connexin signaling use Zonula Occludens protein-1 (ZO-1) as an intermediate. This report describes the ZO-1 and connexin 43 (Cx43) expression pattern in lymphocytes from chronic B-cell leukemia (B-CLL) patients. The ZO-1 and Cx43 expression in the B cells of 113 B-CLL patients was identified. Western blot and flow cytometry were used to determine protein expression. Results indicated that ZO-1 and Cx43 expression was reduced and correlated negatively with CD38 and Zap-70 expression. Inhibition of intercellular communication with anti-Cx43 antibodies, 1-octanol, or carbenoxolone resulted in induced cell apoptosis. These data suggest that ZO-1, along with CD38 and Zap-70, plays a role in cell cycle regulation in B-CLL and may be used as a prognostic marker in B-CLL monitoring.
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Affiliation(s)
- Pavel P Nesmiyanov
- Fundamental Medicine and Biology Department, Volgograd State Medical University, Volgograd, Russia; Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Russia.
| | - Boris E Tolkachev
- Fundamental Medicine and Biology Department, Volgograd State Medical University, Volgograd, Russia; Department of Hematology, Volgograd Regional Clinical Oncology Dispensary No.1, Volgograd, Russia
| | - Andrey V Strygin
- Fundamental Medicine and Biology Department, Volgograd State Medical University, Volgograd, Russia; Volgograd Medical Science Center, Pharmacology Department, Laboratory for Genomics and Proteomics, Volgograd, Russia
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